The Positive Attitudes in Tennessee Schools Project (PATS), a collaborative school-improvement effort, was implemented in Tennessee schools in 1989. The project is based on the premise that a cultural transformation in the schools is needed to provide more supportive learning environments. This paper presents findings of a longitudinal study that sought to determine the extent of changes in the participating schools' cultural environments. In spring 1993, a total of 92 schools (51 elementary, 21 middle, and 20 high schools) participated in a school climate audit, which measured seven school climate factors through the Tennessee School Climate Inventory. A multivariate analysis of covariance (MANCOVA) was conducted to assess the impact of the program on the seven dependent variables (school climate factors). Findings indicate that overall, school climate dimensions remained relatively stable over time. However, the program has had the greatest effect on transforming instructional values and practices at the elementary level. Results point to the resiliency of school climates to change. Some research suggests that the impacts of educational reform take 3 to 5 years to materialize. Three tables are included. (LMI)